The present invention relates to an arrangement for cooling an internal combustion engine for a vehicle, such as an automobile, when the vehicle is at a standstill or slowly moving, so that difficulties in restarting the heated engine are avoided. Such difficulties occur, in particular, when the vehicle is stopped and the engine shut off following operation under a full load, especially with high ambient temperatures and in a vehicle having an air-cooled engine. The fuel that remains in the fuel pump and/or in the carburetor float chamber evaporates due to the high temperatures within the engine housing, making the engine difficult to restart.
To avoid difficulties in restarting a heated engine, additional cooling of the engine should be provided when the primary cooling system for the engine no longer functions at optimum effectiveness. In water-cooled engines, for example, the primary cooling system for the engine ceases to function when the engine is shut off and the cooling water stops circulating. In air-cooled engines, the primary cooling system functions less effectively whenever the flow of cooling air over the engine is reduced (i.e. whenever the automobile slows down). A critical reduction in cooling air flow may occur even while the vehicle is still moving slowly.
German Pat. No. 1,007,564 discloses a cooling arrangement for an internal combustion engine in which the housing for the engine is provided with two vertically spaced openings, the lower of which is provided with a swiveling flapvalve cover. Air is forced by a blower through the engine housing from the upper opening to the lower opening. The temperature within the engine housing is controlled by opening or closing the lower opening with the swiveling flap-valve cover, which is actuated by a thermostat located within the engine housing. The patented cooling arrangement, however, is intended to cool the engine under normal operating conditions, and not to cool a heated, stationary engine in order to avoid difficulty in later restarting the engine.
Another cooling arrangement is described in "Automobiltechnischen Handbuch" (Handbook of Automotive Engineering), 16th edition 1945, at page 1194. In the described arrangement, the quantity of cooling air is adjusted in accordance with the fuel supply to the engine partly by making use of the vacuum in the engine intake manifold. Again, the cooling arrangement is not directed to overcoming the difficulties in restarting a heated engine.